نتایج جستجو برای: higher order aberration

تعداد نتایج: 1779750  

2015
Uzeyir Erdem Fatih C. Gundogan Umut Aslı Dinc Umit Yolcu Abdullah Ilhan Salih Altun

Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil si...

Journal: :Journal of microscopy 2016
Martin Skorsetz Pablo Artal Juan M Bueno

A wavefront sensorless adaptive optics technique was combined with a custom-made multiphoton microscope to correct for specimen-induced aberrations. A liquid-crystal-on-silicon (LCoS) modulator was used to systematically generate Zernike modes during image recording. The performance of the instrument was evaluated in samples providing different nonlinear signals and the benefit of correcting hi...

Journal: :Vision Research 2011
Fan Yi D. Robert Iskander Michael Collins

It is known that the depth of focus (DOF) of the human eye can be affected by the higher order aberrations. We estimated the optimal combinations of primary and secondary Zernike spherical aberration to expand the DOF and evaluated their efficiency in real eyes using an adaptive optics system. The ratio between increased DOF and loss of visual acuity was used as the performance indicator. The r...

Journal: :Applied optics 2005
Sjoerd Stallinga

Spherical aberration arising from deviations of the thickness of an optical disc substrate from a nominal value can be compensated to a great extent by illuminating the scanning objective lens with a slightly convergent or divergent beam. The optimum conjugate change and the amount and type of residual aberration are calculated analytically for an objective lens that satisfies Abbe's sine condi...

Journal: :بینا 0
افشین لطفی صدیق a lotfi sedigh tabriz university of medical sciences, tabriz, iranدانشگاه علوم پزشکی تبریز- تبریز- ایران عبداله شناسی a shenasi tabriz university of medical sciences, tabriz, iranدانشگاه علوم پزشکی تبریز- تبریز- ایران تهمینه آرین t aryan tabriz university of medical sciences, tabriz, iranدانشگاه علوم پزشکی تبریز- تبریز- ایران

purpose: the aim of this study was to compare higher-order aberrations between personalized treatment (pt) versus personalized treatment advanced (pta) photorefractive keratectomy (prk) for myopia and myopic astigmatism. methods: in this clinical trial, 80 eyes of 40 patients who met inclusion criteria were enrolled. they underwent prk using pt or pta algorithm randomly. higher-order aberration...

Journal: :Vision Research 2010
Nancy J. Coletta Susana Marcos David Troilo

The common marmoset, Callithrix jacchus, is a primate model for emmetropization studies. The refractive development of the marmoset eye depends on visual experience, so knowledge of the optical quality of the eye is valuable. We report on the wavefront aberrations of the marmoset eye, measured with a clinical Hartmann-Shack aberrometer (COAS, AMO Wavefront Sciences). Aberrations were measured o...

2015
Mustafa Demir Sevda Aydin Kurna Tomris Sengor Tugba Gencaga Atakan Tayfun Sahin

OBJECTIVE To evaluate the aberration and visual quality differences between myopic and astigmatic eyes before and after contact lens application by using corneal aberrometer and low- contrast sensitivity chart. METHODS Eighty eyes of 40 patients were included in this study. Patients were divided into two groups as myopic (40 eyes, n=20) and astigmatic groups (40 eyes, n=20). We used aspheric ...

1993
J. W. de Bakker Franck van Breugel

Semantic models are presented for two simple imperative languages with higher order constructs. In the rst language the interesting notion is that of second order assignment x := s, for x a procedure variable and s a statement. The second language extends this idea by a form of higher order communication, with statements c ! s and c ? x, for c a channel. We develop operational and denotational ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید